Antifibrotic effects of D-limonene (5(1-methyl-4-[1-methylethenyl]) cyclohexane) in CCl₄ induced liver toxicity in Wistar rats

This study was designed to assess the potential antifibrotic effect of D-Limonene—a component of volatile oils extracted from citrus plants. D-limonene is reported to have numerous therapeutic properties. CCl₄-intduced model of liver fibrosis in Wistar rats is most widely used model to study chemopreventive studies. CCl₄-intoxication significantly increased serum aminotransferases and total cholesterol these effects were prevented by cotreatment with D-Limonene. Also, CCl₄-intoxication caused depletion of glutathione and other antioxidant enzymes while D-Limonene preserved them within normal values. Hydroxyproline and malondialdehyde content was increased markedly by CCl₄ treatment while D-Limonene prevented these alterations. Levels of TNF-α, TGF-β, and α-SMA were also assessed; CCl₄ increased the expression of α-SMA, NF-κB and other downstream inflammatory cascade while D-Limonene co-treatment inhibited them. Collectively these findings indicate that D-Limonene possesses potent antifibrotic effect which may be attributed to its antioxidant and anti-inflammatory properties.